Multiple break circuit interrupter



Aug. 2, 1949.

w. M. LEEDS ETAL 2,477,810

MULTIPLE BREAK CIRCUIT INTERRUPTER Filed Aug. 15, 1944 7 Sheets-Sheet 1Jameg /W. Gum/72mg. I

ATTORN A g- 2, 949 w. M. LEEDS ET AL 2,477,810

MULTIPLE BREAK CIRCUIT INTERRUPTER Filed Aug. 15, 1944 7 Sheets-Sheet 2WITNESSES: "gENTOgS m rap ea 5 an James M Cumming. don-F a Y A'ITORNAllg- 1949. w. M. LEEDS ETAL 2,477,810

MULTIPLE BREAK CIRCUIT INTERRUPTER Filed Aug. 15, 1944 7 Sheets-Sheet 3INVENTORS Winthrop M. Leeds and James M Uummmg.

2, 1949; w. M. LEEDS ET AL 2,477,810

MULTIPLE BREAK CIRCUIT INTERRUPTER Filed Aug. 15, 1944 7 Sheets-Shee 4INJENTORS Winthrop Leeds and James 011mm 272g.

1949- w. M. LEEDS ET AL 2,477,810

MULTIPLE BREAK CIRCUIT INTERRUPTER Filed Aug. 15, 1944 '7 Sheets-Sheet 5Magnetic 4 Material Magnetic Material v INVENTORS Winthrop M Leeds andJames MGummz'ng.

WITNESSES:

1949. w. M. LEEDS ETAL 2,477,810

MULTIPLE BREAK CIRCUIT INIERRUPTER Filed Aug. 15, 1944 7 Sheets-Shelet 6I ES: INVENTORS ZQ Winthrop MLaeds andfames'fil Cumming.

Aug. 2, 1949. w. M. LEEDS ETAL 2,477,810

MULTIPLE BREAK CIRCUIT INTERRUPTER Filed Aug. 15, 1944 7 Sheets-Sheet 7III III Ill/Ill I Y/I/l'.

\\' \\\\\\\\\\\\\\\n FIRE 105 .L' I 4 g 1o .wnussszs: INVENTORS WimkrapM Leeds and 4%. James M Cumming.

I q a zm Patented Aug. 2, 1949 UNITED STATES PATENT OFFICE 2,477,810MULTIPLE BREAK cmomr m'rnnaur'raa Winthrop M. Leeds, Forest Hills, andJames M.

Cumming, Turtle Creek, Pa... assignors to Westinghouse ElectricCorporation, East Pittsburgh, Pa., a corporation of PennsylvaniaApplication August 15, 1944, Serial No. 549,576

27 Claims. 1 i

This invention relates to circuit lnterrupters in general and, moreparticularly, to circuit interrupters of the liquid break type.

In addition to the fundamental function of interrupting its ratedcurrent capacity at rated voltage, the modern circuit breaker shouldhave the ability to operate at very high speed (total time fromenergizing thetrip coil to are extinction being as low as 3 to cycles at60 cycles frequency). Also it has been found desirable to interrupt lowcurrent values, such as magnetizing or line charging currents (usuallybelow 25% of rating), almost as fast as short circuit currents to avoidthe possibility of objectionable switching surges.

In United States patent application Serial No. 468,454, filed December10, 1942, by Robert C. Dickinson, now U. S. Patent 2,394,046, issuedFebruary 5, 1946, and assigned to the assignee of the instantapplication there is disclosed and claimed a novel operating arrangementfor simultaneously effecting the operation of two serially related arcextinguishing units. In this application rotatable lever means areemployed to simultaneously effect the operation of two movable contactstructures. It is an object of our invention to improvise an improvedoperating arrangement over the arrangement disclosed in thisapplication.

Also in United States patent application Serial No. 471,847, filedJanuary 9, 1943, by Benjamin P. Baker, now U. S. Patent 2,412,857,issued December 17, 1946, and assigned to the assignee of the instantapplication there is disclosed and claimed an operating arrangementwhich simultaneously effects the operation of a plurality of movablecontact structures employing lever means to eifect their actuation. Anoperating rod is also utilized to simultaneously efiect the operation ofthe lever means during the opening operation oi the interrupter. It isan object of our invention to further improve the operating arrangementdisclosed in this patent application.

Another object is to provide an improved circuit interrupter in which aplurality of serially related arc extinguishing units are employed, andto provide interconnecting passage means between the units so thatpressure generated in certain units may be utilized to efiect the flowof fluid through the passage means into other units to facilitate theextinction of the arcs drawn in the other units.

Another object is to provide an improved circuit interrupter in whichtwo are extinguishing units are employed and to provide contact means 2operative in each unit to establish an arc. We provide rotatableactuating means for simultaneously effecting the operation of bothcontact means.

Further objects and advantages will readily become apparent upon thereading of the following specification taken in connection with thedrawings, in which:

Figure 1 is a vertical sectional view of an arc extinguishing assemblageembodying our invention and shown in the closed circuit position;

Fig. 2 is an enlarged vertical sectional view of the upper two areextinguishing units of Fig. l, the movable parts being shown in thepartly open circuit position;

Fig. 3 is a vertical sectional view taken along the line IIIIH of Fig.7;

Fig. 4 is a plan view in section taken along the line IVIV of Fig. 2;

Fig. 5 is a plan view in section taken along the line V--V of Fig. 2;

Fig. 6 is a plan view in section taken along the line VI-VI of Fig. 2;

Fig. 7 is a plan view in section taken along the line VII-VII of Fig. 2;

Fig. 8 is a plan view in section taken along the line VIII-VIII of Fig.2;

Fig. 9 is a plan view in section taken along the line IX-IX of Fig. 2;

Fig. 10 is a plan view in section taken along the line X-X of Fig. 2;

Fig. 11 is a schematic view of a modified type of arc extinguishingassemblage embodying our invention, the disposition of the parts beingin an intermediate point in the opening operation;

Figs. 12 through 19 show plan views of plate details used in theconstruction of the are extinguishing units employed in Fig. 1;

Fig. 20 shows a modified type of upper arc extinguishing unit employedin the assemblage of Fig. 1, the parts being shown in the partly opencircuit position;

Fig. 21 is a plan view in section taken along the line XXI-XXI of Fig.20;

Fig. 22 is another modified type of upper are extinguishing unit whichmay be used in place of the upper arc extinguishing unit of Fig. 1, theparts being shown in the partly open circuit position;

Fig. 23 is an enlarged vertical sectional view taken through themodified type of arc extinguishing unit shown in Fig. 22 along the lineXXIII-m1 of Fig. 24; and

Fig. 24 is a plan view in section taken along the line XXIV-XXIV of Fig.22.

Referring to the drawings and more particularly to Fig. 1, the referencenumeral I generally designates an arc extinguishing assemblage which maybe suspended in a tank 2 (Fig. 11) by suitablemeans well known in theart. An arc extinguishing fluid 3, such as oil. fills the tank 2 to thelevel 3a thereby completely immersing the arc extinguishing assemblageI. Referring again to Fig. 1 the arc extinguishing assemblage I, in thisinstance, comprises three serially related arc extinguishing unitsgenerally designated by the reference numeral 4 and disposed in asuperimposed spaced relation. A contact means is operative in each unit4 to establish an arc therein. In the upper or end unit 4 the contactmeans comprises a stationary contact 5 having a stud portion 6 extendingthrough the top casting plate I of the assemblage I and secured theretoby nuts 8, and a movable contact 9 having a pin I8 extendingtherethrough which is engaged by a rotatable actuating means generallydesignated by the reference numeral I I.

An identical rotatable actuating means II is disposed between the centerunit 4 and the lower or end unit 4. The two rotatable actuating means IIefiect the operation of the two movable contacts |2,I3 operative withinthe center unit 4. The lower rotatable actuating means II also causesthe operation of the movable contact I4 associated with the lower arcextinguishing unit 4. Cooperable with the movable contact I4 is astationary contact I5 secured by suitable means (not shown) to thebottom plate casting I6.

During the opening operation the several contacts are actuated byrotative movement of the rotatable actuating means II to establish anarc in each arc extinguishing unit 4. We provide fluid passage meansgenerally designated by the reference numeral II interconnecting thethree are extinguishing units 4. In this instance the fluid passagemeans I1 comprises conduits I8 formed in a casting I9 disposed betweenthe center unit 4 and each end unit (see Figs. 3 and 7). The casting I9has integrally formed therewith support brackets (Fig. 7) through whichpasses a pin 2| pivotally supporting lever means generally designated bythe reference numeral 22. In this instance the lever means 22 comprisestwo levers 23 pivotally supported on the pin 2| and having supported attheir opposed ends pins I0 and 24. The pin 24 causes the operation ofthe movable contact I2 of the central unit 4, and the pin III causesoperation of the movable contact 9. Forming an extension of the movablecontact 9 is a piston member 25 which moves into and out of central unit4 during the opening and closing operation, the purpose for which willappear more clearly hereinafter. Also associated with the movablecontact I4 is a piston member 26 which moves into and out of the centralunit 4.

The two rotatable actuating means II are simultaneously operated byvertical reciprocating motion of two insulating operating rods 21 whichare actuated by the vertical reciprocating motion of the conductingbridging member 28, the latter electrically interconnecting the two areextinguishing assemblages I disposed in the tank 2 connects the member38 with the plate casting I6.

contact I2, movable contact I3, conductor 33,

movable contact I4, stationary contact I5, plate I6, conductor 32,member 30, disconnect fingers 3|, through the conducting bridging member28 and finally through the right-hand arc extinguishing assemblage I inan identical manner to the right-hand terminal stud not shown.

The operating rods 21 have clamped thereto brackets 31 (Fig. 7) whichsupport pins 38 which also pass through the levers 23 to cause theactuation thereof. It will be observed, referring to Fig. 1,. that thepin 38 associated with the upper rotatable actuating means I I is to theright of the pin 2|, whereas the pin 38 associated with the lowerrotatable actuating means II is disposed to the left of the pin 2|.Consequently, during the closing operation the upper actuating means IIcauses a counterclockwise rotation of the lever means 22, whereas thelower actuating means II causes a clockwise rotation of the lower levermeans 22.

The construction of the arc extinguishing unit 4 will now be described.With reference to the central arc extinguishing unit 4 it will beobserved that immediately below the casting I9 is an insulating plate 39having a configuration more clearly shown in Fig. 15. The plate 39 hastwo apertures 40 formed therein for the accommodation of insulating tierods 4| (Fig. 10). The tie rods 4| function to maintain the platesfixedly in position and extend through all of the units 4. Additionaltie rods 42 (Fig. 1) composed of insulating material extend between theplates I and the plate It exteriorly of the units 4 and nuts 43 securethe rods 42 to bosses 44 integrally formed with the plates I and I6.

The insulating plate 39 (Fig. 10) also has two apertures 45 formedtherein through which loosely pass the operating rods 21. Apertures 46are provided in the plate 39 to help form the fluid passage means II. Anaperture 47 is provided to accommodate the motion of the piston member25. An aperture 43 is provided to accommodate the movable contact I2,the aperture 48 communicating with a cutout portion generally designatedby the reference numeral 49 and forming four pockets 58. Below the plate39 is a second plate 33 which is followed by a magnetic insert plategroup generally designated by, the reference numeral 5|.

The plate group 5| comprises a group of three plates, the outer two ofwhich are designated by the reference numeral 52 (Fig. 16) and areherein called guard plates. The insulating guard plates 52 (Fig, 16)have apertures 48, 45, and 46. The guard plate 52 has formed therein acut-out portion 54. Between the insulating guard plates 52 is aninsulating magnetic insert plate 55 having a configuration more clearlyshown in Fig. 17. The insert plate 55 has the apertures 48, 45, 46 and41 with a cut-out portion defined by the outer full line 56 in Fig. 17.Positioned within the cutout portion 56 is a U-shaped insert 51 composedof a magnetic material, in this instance iron, the purpose for whichwill appear more clearly hereinafter. Positioned within the magneticinsert is an insulating liner plate 58 having a thickness equivalent tothe thickness of two of the guard plates 52 and one insulating plate 55.Consequently, when the insert plate 55 is positioned between twoinsulating guard plates 52 the thickness of the liner plate 58 issuflicient to extend through all three plates.

The liner plate 58 has an aperture 48 formed therein to accommodate themovable contact l2 which communicates with the cut-out portion 59.Referring to Fig. 2 it will be observed that below the magnetic insertgroup 5| is a third plate 39, which is followed by a second group 5|.Below the second group 5! is positioned an insulating flow plate 60having a configuration more clearly shown in Fig. 19 of the drawings.The plate 60 has apertures 40, 45, 46, 41 and two connecting passages53. The plate 66 also has an aperture 48, cut-out portion 43 formingfour pockets 56 and leading by a passage 6| to the aperture 41.

Referring to Fig. 2 it will be noted that below the flow plate 60 is agroup 5|, a second flow plate 60, group 5|, two iiow plates 66, group5|, plate 60, group 5|, plate 60, group 5|, plate 39, group 5|, and twoplates 39. It will consequently be apparent that the plate groupingabove and below the line 62 is symmetrical.

The interrupting structure associated with the end units 4'will now beexplained. Immediately below the top casting plate I are two insulatingplates 63 having a configuration more clearly shown in Fig. 12 of thedrawings. Each plate 63 has apertures 40, 45, 46, an aperture 64 toaccommodate the stationary contact 5. The aperture 64 leads by way ofthe passage 65 to a cut-out portion generally designated by thereference numeral 56 forming four pockets 56 and leading by way of apassage 61 to an aperture 68. Below the two plates 63 is a magneticinsert plate group generally designated by the reference numeral 69. Thegroup 59 comprises two insulating guard plates having a configurationmore clearly shown in Fig. 13 and a magnetic insert plate H composed ofinsulating material and having a configuration more clearly shown inFig. 14 of the drawings. The plates 10, II have apertures 40, 45, 46.The guard plate 10 has a cut-out portion 54 and the magnetic insertplate H has a cut-out portion 56 in which is positioned a magneticinsert 51. An insulating liner plate 12 is provided having a thicknessequivalent to two guard plates 16 and one insert plate H. The two plates16 and the plate H are assembled in a manner as previously described.

Referring to Fig. 2 it will be noted that below the plate group 69 is athird plate 63 which is followed by a plate group 63, plate 63, plategroup 69, plate 63, plate group 69. Below the last mentioned plate group69 are two insulating plates 13 having a configuration more clearlyshown in Fig. 18 of the drawings. Each insulating plate 13 has apertures40, 45, 46, 64, passages 53, 65, cutout portion 56, forming four pockets50, a passage 61, leading to an aperture 66.

Referring to Fig. 2 it will be observed that below the second insulatingflow plate 13 is a group 69, insulating flow plate 13, group 69, flowplatev'l3, group 63, plate 63, group 69 and two plates 63. Theinterrupting structure associated with the lower arc extinguishing unit4 is identical to the interrupting structure associated with the upperarc extinguishing unit 4 and therefore need not be described.

The operation of the arc extinguishing assemblage I will' now bedescribed. When it is desired to open the electrical circuit passingthrough the interrupter, or in response to overload conditions springs29 to force the member 30 and hence the insulating operating rods 21downwardly. The

" downward movement of the operating rods 21 causes the operation of thetwo rotatable actuating means ii to effect thereby a separation of thecontact means associated with each of the units 4. The result is thedrawing of a pressure-gen-' erating are 14 between-the contacts l2, I3in the center unit 4 and the drawing of two interrupting arcs 15 in thetwo end units 4, as more clearly shown in Fig. 2. Simultaneously thepiston members 25, 26 enter the central unit 4 to apply pressure toassist low current interruption when the pressure generated at thepressure-generating arc 14 may not be sufficient to establish therequisite velocity of oil flow adjacent the two interrupting arcs 15 toeffect their extinction.

The magnetic field about the pressure-generating are 14 is distorted bythe presence of the magnetic inserts 51 associated with the groups 5| toconsequently cause the lateral motion of the pressure-generating are 14to the right as viewed in Fig. 2. The rightward motion of thepressuregenerating are 14 causes it to move into the cutout portion 49(Fig. 19) to engage additional oil retained in the pockets 50 disposedin the insulating plates 60 and plates 39. This increases the pressureestablished at the pressure-generating arc. The pressure thus generatedby the pressure-generating are [4 acts through the passages 6| providedin the plates 60, through the passages 53 associated with the plates 66and upwardly and downwardly through the conduits l8 as more clearlyshown in Fig. 3.

Considering only the upward flow of fluid through the conduits l8associated with the upper casting I9, it will be observed that the oilflows through the passages 53 provided by the plates I3 to engage theupper interrupting arc l5 and to pass out of the upper unit 4 by meansof the vent opening 15 formed by the apertures 66 provided in the plates63, 10, H and.'l3. The direction of the oil flow is as indicated by thearrows in Fig. 2. A similar action takes place in the lower arcextinguishing unit 4.

It will be observed that not only is the interrupting are 15 subjectedto an oil flow passing through the passages 53 of the plates 13, butalso the interrupting are 15 is magnetically moved to the left as viewedin Fig. 2 by the distorted magnetic field thereabout as effected by thepresence of the magnetic inserts 51 associated with the groups 69. Thecombined effect of the oil flow and the magnetic reaction moves theupper terminal of the interrupting are 15 onto the arcing horn H topermit the are 15 to be rapidly lengthened. The oil passes out of theupper unit 4 through a recessed portion 18 formed in the plate 1.

As mentioned previously during low current interruption the pistonaction caused by the piston 25, 26 entering the central unit 4 createsthe requisite oil flow adjacent the interrupting arcs 15.

From the foregoing description it will be apparent that we have provideda novel are extinguishing assemblage comprising three serially relatedsuperimposed arc extinguishing units, the center one of which issubstantially enclosed and speed of separation of the movable contactsmay be greatly increased over the downward speed of the movableoperating rods 21. This results because of the different lever arms Rand R as indicated in Fig. 2.

The novel circuit interrupter described above has been designed tointerrupt low current values, such as magnetizing or line chargingcurrents almost as fast as short-circuit currents to avoid thepossibility of objectionable switching surges, and test made on theforegoing device indicate the ability of the interrupter to interruptwith high speed short-circuit currents over a wide range of currentvalues. Because of the lever ratio R R, the arcing contacts move withapproximately twice the speed of the operating rods 21. Furthermore,since there are two movable contacts |2, '|3 moving in oppositedirections in the central unit 4, the speed of the break here is twicethat of the breaks in the end units 4.

If found desirable, an extra lever 23 may be associated with thestationary contact of the top unit 4 and with the stationary contact l5associated with the bottom unit 4 to operate a second movable contact(not shown) in these end units also. A fragmentary view of such amodified type of operating arrangement together with a modified type ofarc extinguishing structure is shown in Figs. 20 and 21. Referring tothese figures it will be observed that an extra lever 23 is associatedwith a movable contact 18 which takes the place of the stationarycontact 5 utilized in the structure previously described. If desired, anadditional accelerating compression spring 88 may be positioned at theupper ends of the two operating rods 21. Two brackets 31 may be clampedto the upper ends of the rods 21 to rotate the levers 23 about the fixedpin 2| bymeans of the pin 38. Thus during the closing stroke the lever23 is rotated in a clockwise direction about the pin 2| and during theopening stroke the lever 23 is rotated in a counterclockwise directionabout the pin 2| to effect a more rapid lengthening of the interruptingare 15 drawn between the contacts 8, 18. In like manner the lower arcextinguishing unit 4 could be modified by the addition of an extra lever23 to actuate a movable contact, not shown, which could take the placeof the stationary contact IS.

The modified type of are extinguishing structure associated with themodified type of are extinguishing unit 8| will now be explainedReferring to Figs. 20 and 21 it will be observed that there are disposedwithin the unit 8| a plurality of magnetic insert groups generallydesignated by the reference numeral 82. Each group 82 comprises threeinsulating plates suitably formed with an insulating liner plate havinga thickness equivalent to the aforesaid three plates. More specifically,the outer plates of the group 82 have a configuration more clearly shownin Fig. 21 and may be designated by the reference numeral 83. Each ofthe plates 88 is of insulating material and has a portion thereofdesignated by the line 84 in Fig. 21 removed therefrom. Between twoinsulating guard plates 83 is a magnetic insert plate designated by thereference numeral 85 which has an enlarged portion designated by thedotted line 86 in Fig. 21 removed therefrom. In this enlarged portion isplaced a U-shaped magnetic insert 81 composed of magnetic material, inthis instance iron. A liner insulating plate 88 is employed having anenlarged portion 89 and a restricted portion 98, the purpose for whichwill appear more fully hereinafter. Between adjacent groups 82 arepositioned insulating vent plates 8| having a configuration more clearlyshown in Fig. 21. The vent plates 8| have passages 82 connecting theopenings 46 with the interrupting are 15. The vent plates 9| also havevent openings 93 permitting a venting of oil from within the unit 8| tothe region exterior of the unit. The vent plates 9| also form aplurality of pockets 58 which serve to retain a plentiful supply of oiladjacent the interrupting are 15 a it is moved toward the left as viewedin Figs. 20 and 21.

The operation of the modified type of unit 8| will now be explained.During the opening operation the insulating operating rods 21 movedownwardly to effect a downward motion of the movable contact 9 and anupward motion of the movable contact 19 to draw the interrupting are 15therebetween, The magnetic inserts 81 bias the are 15 toward the left.During relatively high instantaneous values of arcing current, that isduring the peak of the alternating current wave, the cross-sectionalarea of the interrupting are 15 is too large to permit it to be biasedinto the restricted portion 88. It is only during relatively lowinstantaneous values of arcing current, that is, near a current zero, ata time suitable for interruption, that the cross-sectional area of theinterrupting arc I5 is sufliciently small for it to enter the restrictedportion 98 under the influence of the magnetic inserts 81. While it isin the restricted portion 98 it engages fresh oil disposed in thepockets 58 and is also subjected to a blast of oil passing upwardlythrough the two conduits l8, through the passages 82 and into theportions 89 and 98. The combined effect of the flow creates turbulencewhich effects extinction at an early current zero. The upper terminal ofthe are 15 may transfer to the arcing horn 11 to effect a rapidlengthening thereof. Certain features of this interrupting structure aredescribed and claimed in a patent application filed September 18, 1942,Serial No. 458,778, by Winthrop M. Leeds and Benjamin P, Baker, nowPatent 2,372,589, issued March 27, 1945, and assigned to the sameassignee as the instant application. The combined effect of the oil flowand the magnetic reaction will cause the are 15 to lengthen faster thanthe speed of separation of the contacts 8, 18 as indicated by the dottedline 84.

Figs, 22 through 24 show a modified type of interrupting structure whichmay be used in modified type end are extinguishing units generallydesignated by the reference numeral 91. Certain features of thisinterrupting structure are described and broadly claimed in a patentapplication filed November 11, 1942, Serial No. 465,244, by Leon R.Ludwig, Winthrop M. Leeds and Benjamin P. Baker, now U. S. Patent2,406,469, issued August 27, 1946, and assigned to the same assignee asthe instant application.

In the modified arc extinguishing structure 81 the movable contact 8separates from the stationary contact 5 to draw the interrupting are 15.Above the level indicated by the dot and dash line 88 the plates of theunit 91 merely have apertures 89 formed therein to align in forming thevent passage I88. These plates are of two types and may be designated bythe reference numeral IM and I82. The plates |8| have a smaller apertureI83 than have the plates |82 at I84. Of course, the plates |8l, I82 haveapertures 48 and 40 to accommodate the insulating tie rods II and theoperating rods 21 respectively.

The vent passage I leads out of the unit 91 by means of a pair ofopenings 99a provided in two of the plates I02 and the recessed portionI8 formed in the plate 1. V

Below the level 90 in the unit 81 the plates are of three difierenttypes and may be designated by the reference numeral I05, I00 and I01.The insulating plates I05 have a configuration more clearly shown inFig. 24. The plates I05 have passages I08 interconnecting the openings46 with an enlarged opening I09. The plates I05 may be designated inletplates. The plates I0 6 may be designated exhaust plates and having aconfiguration indicated by the dotted line I I0 in Fig. 24, permittingan exhausting of fluid adjacent the are 15 out through a vent-passageIII (Fig. 24) to the vent I00. plates I05 and exhaust plates I08 areinsulating orifice plates designated by the reference numeral I01 andmerely having an orifice II! of slightly larger diameter than thediameter of the movable contact 9.

During the opening operation oil passes upwardly through the conduits I8in casting I9 to pass in the inlet passages I00 (Fig. 23) to strike theinterrupting are 15 at a plurality of points as the latter islengthened. This oil is caused to engage the arc I5 by being compelledto pass through the orifices I I! as it exhausts out of the ventpassages III provided in the insulating exhaust plates I00 to the ventopening I00. Consequently, in this embodiment of our invention weprovide means in at least one end unit 91 for forcing a plurality ofjets of liquid at the arc drawn therein and permit an exhausting ofliquid from the arc at a. plurality of intermediate points.

Referring to Fig. 11 it will be observed that we provide a modified typeof arc extinguishing assemblage generally designated by the referencenumeral H3 and comprising a plurality of, in this instance five, areextinguishing units 4 schematically indicated. The arc extinguishingunits 4 are numbered by the Roman numerals IV. In this arrangement offive units two moving contacts operate in units II, III and IV and onemoving contact in the top and bottom unit I and V. The high pressureunits are units II and IV which force oil by means of the fluid passagemeans II into the vented units 1, III and V.

Since the middle unit III has oil forced into it from two directions,and since the contact break speed here is twice that of the speed of thebreak.

in the end units I, V, it should have twice as many vents as end unitsI, V as indicated by the four arrows I I4, whereas the end units onlyhave venting proportional to two arrows II5.

In order to avoid high pressure in the units II and IV from acting onthe pistons so as to tend to close the contacts against the openingforce of the accelerating compression spring 29, it is desirable thatthe cross-sectional area of each piston should not exceed twice thecross-sectional area of each moving contact, since the force on twomoving contacts moving out of the unit will balance the force on onepiston moving into the unit.

From the foregoing description of specific embodiments of our inventionit will be apparent that we have provided an improved operatingarrangement for a circuit interrupter and also Between adjacent inletimproved interrupting structure to effect a breakguishing units in whichone or more units are substantially enclosed and serve as pressure unitsto force oil by interconnecting passage means into other units of theassemblage which are vented. We have disclosed a means whereby the speedof separation of the movable contacts may be much Although we have shownand described specific structures, it is to be clearly understood thatthe same were merely for purposes of illustration and that changes andmodifications may be made therein by those skilled in the art withoutdeparting from the spirit and scope of the appended claims.

We claim as our invention:

1. In a circuit interrupter of 'the liquid break type, an arcextinguishing assemblage comprising three serially related arcextinguishing units disposed in superimposed relation, a stationarycontact disposed in each end unit, a movable contact cooperable witheach stationary contact to establish an arc in each end unit, twomovable contacts movable within the center unit, a first lever meansinterconnecting the movable contact associated with an endunit with oneof the two movable contacts associated with the center unit, and asecond lever means interconnecting the movable contact associated withthe other end unit with the other movable contact associated with thecenter unit.

2. In a circuit interrupter of the liquid break type, an arcextinguishing assemblage comprising three serially related arcextinguishing units disposed in superimposed relation, a stationarycontact disposed in each end unit, a movable contact cooperable witheach stationary contact to establish an arc in each end unit, twomovable contacts movable within the center unit, a first lever meansinterconnecting the movable contact associated with an end unit with oneof the two movable contacts associated with the center unit, a secondlever means interconnecting the movable contact associated with theother end unit with the other movable contact associated with the centerunit, and fluid passage means interconnecting the three units.

3. In a circuit interrupter of the liquid break type, an arcextinguishing assemblage comprising three serially related arcextinguishing units disposed in superimposed relation, a stationarycontact disposed in each end unit, a movable contact cooperable witheach stationary contact to establish an arc in each end unit, twomovable contacts movable within the center unit, a first lever meansinterconnecting the movable contact associated with an end unit with oneof the two movable contacts associated with the center unit, a secondlever means interconnecting the movable contact associated with theother end unit with the other movable contact associated with the centerunit, and fluid passage means interconnecting the three units, thecenter unit being substantially enclosed, the two end units being ventedso that pressure generated within the center unit will act through thefluid passage means to facilitate the extinction of the two arcs drawnin the two end units.

4. In a circuit interrupter of the liquid break type, an arcextinguishing assemblage comprising three serially related arcextinguishing units disposed in superimposed relation, astationary-contact disposed in each end unit, a movable contactcooperable with each stationary contact to establish an arc in each endunit, two movable contacts movable within the center unit, a first levermeans interconnecting the movable contact associated with an end unitwith one of the two movable contacts associated with the center unit, asecond units, the center unit being substantially enclosed,

the two end units being vented so that pressure generated within thecenter unit will act through the fluid passage means to facilitate theextinction of the two 'arcs drawn in the two end units, a piston memberassociated with each lever means and movable into the center unit duringthe opening operation, magnetic means associated with each unit to causelateral motion of the are drawn in each unit during all instantaneousvalues of arcing current.

5. In a circuit interrupter of the liquid break type, an arcextinguishing assemblage comprising three serially related arcextinguishing units disposed in superimposed relation, a stationarycontact disposed in each end unit, a movable contact cooperable witheach stationary contact to establish an arc in each end unit, twomovable contacts movable within the center unit, a first lever meansinterconnecting the movable contact associated with an end unit with oneof the two movable contacts associated with the center unit, a secondlever means interconnecting the movable contactassociated with the otherend unit with the other movable contact associated with the center unit,fluid passage means interconnecting the three units, the center unitbeing substantially enclosed, the two end units being vented so thatpressure generated within the center unit will act through the fluidpassage means to facilitate the extinction of the two arcs drawn in thetwo end units, a piston member associated with each lever means andmovable into the center unit during the opening operation, magneticmeans associated with each unit to cause lateral motion of the arc drawnin each unit, and means in at least one end unit to prevent lateralmotion of the arc drawn therein except only during relatively lowinstantaneous values of arcing current.

6. In a circuit interrupter of the liquid break type, an arcextinguishing assemblage comprising three serially related arcextinguishing units disposed in superimposed relation, a stationary contact disposed in each end unit, a movable contact cooperable with eachstationary contact to establish an arc in each end unit, two movablecontacts movable within the center unit, a first lever meansinterconnecting the movable contact associated with an end unit with oneof the two movable contacts associated with the center unit, a secondlever means interconnecting the movable contact associated with theother end unit with the other movable contact associated with the centerunit, fluid passage means interconnecting the three units, the centerunit being substantially enclosed, the two end units being vented sothat pressure generated within the center unit will act through thefluid passage means to facilitate the extinction of the two arcs drawnin the two end units, a piston member associated with each lever meansand movable into the center unit during the opening operation, and meansin at least one end unit for forcing a plurality of jets of liquid atthe are drawn therein and permitting the exhausting of liquid from theare at a plurality of intermediate points.

a,477,ero

7. In a circuit interrupter, an arc extinguishing assemblage comprisingtwo serially related arc extinguishing units dtsposed in axially alignedrelation, rotatable lever means positioned between the two units, meanspivotally'mounting the lever means intermediate its ends, a movablecontact connected to the lever means adjacent one end thereof andmovable within one of the two units, another movable contact connectedto the lever means adjacentthe other end of the lever means and movablewithin the other unit, a piston member forming an extension of thesecond-mentioned movable contact and movable into the firstmentionedunit, and fluid flow passage means interconnecting the two units.

8. In a circuit interrupter, an arc extinguishing assemblage comprisingtwo serially related arc extinguishing units disposed in axially alignedrelation, rotatable lever means positioned between the, two units, meanspivotally mounting the lever means intermediate its ends, a movablecontact connected to the lever means adjacent one end thereof andmovablewithin one of the two units, another movable contact connected to thelever means adjacent the other end of the lever means and movable withinthe other unit, a piston member forming an extension of thesecond-mentioned movable contact and movable into the firstmentionedunit, an operating rod movable axially of the two units, means pivotallyinterconnecting the operatin rod and the lever means, and a conductingmember for engaging the operating rod in abutting relation to cause theclosing mo tion thereof.

9. In a circuit interrupter, an arc extinguishing assemblage comprisingtwo serially related arc extinguishing units disposed in axially alignedrelation,rotatable lever means positioned between the two units, meanspivotally mounting the lever means intermediate its ends, a movablcontact connected to the lever means adjacent one end thereof andmovable within one of the two units, another movable contact connectedto the lever means adjacent the other end of the lever means and movablewithin the other unit, and passage means interconnecting the two unitsso that the are established in one of the units may force fluid throughthe passage meansint'o the other unit,

10. In a circuit interrupter, an arc extinguishing assemblage comprisingthree serially related arc extinguishing units disposed in axiallyaligned relation, 9. first lever means disposed between the middle andupper units, means pivotally mounting the first lever means intermediateits ends, two movable contacts connected to the first lever meansadjacent its two ends, one of the contacts movable within an end unitand the other movable contact movable within the center unit, a secondlever means disposed between themiddie and lower units, means pivotallymounting the second lever means intermediate its ends, two movablecontacts connected to the second lever means adjacent its two ends, oneof the contacts movable within the center unit, and the other movablecontact movable within the lower unit.

11. In a circuit interrupter, an arc extinguishing assemblage comprisingthree serially related arc extinguishing units disposed in axiallyaligned relation, a first lever means disposed between the middle andupper units, means pivotally mounting the first lever means intermediateits ends, two movable contacts connected to the first lever meansadjacent its two ends, one of the contacts movable within an end unitand the other movable contact movable within the center unit,

, 13 a second lever means disposed between the middle and lower units,means pivotally mounting the second lever means intermediate its ends,two movable contacts connected to the second lever means adjacent itstwo ends, one of the contacts movable within the center unit, the othermovable contact movable within the lower unit, an operating rod movableaxially of the assemblage, and

' means pivotally interconnecting the operating rod and the two levermeans.

12. In a circuit interrupter, an arc extinguishing assemblage comprisingthree serially related arc extinguishing units disposed in axiallyaligned relation, a first lever means disposed between the middle-andupper units, means pivotally mounting the first lever means intermediateits ends, two movable contacts connected to the first lever meansadjacent its two ends, one of the contacts movable within an end unitand the other movable contact movable within the center unit, a secondlever means disposed between the middle and lower units, means pivotallymounting the second lever means intermediate its ends, two movablecontacts connected to the second lever means adjacent its two ends, oneof the contacts movable within the center unit, the other movablecontact movable within the lower unit, and a piston member forming anextension of one of the movable contacts and movable within the unitadjacent to which is the unit in which the movable contact moves.

13. In a circuit interrupter, an arc extinguishing assemblage comprisingthree serially related, arc extinguishing units disposed in axiallyaligned relation, a first lever means disposed between the middle andupper units, means pivotally mounting the first lever means intermediateits ends, two movable contacts connected to the first lever meansadjacent its two ends, one of the contacts movable within an end unitand the other movable contact movable within the center unit, a secondlever means disposed between the middle and lower units, means pivotallymounting the second lever means intermediate its ends, two movablecontacts connected to the second lever means adjacent its two ends, oneof the contacts movable within the center unit, the other movablecontact movablewithin the lower unit, and passage means interconnectingall three units so that pressure generated in the center unit may actthrough the passage means into the two end units.

14. In a circuit interrupter, an arc extinguishing assemblage comprisingthree serially related arc extinguishing units disposed in axiallyaligned relation, a first lever means disposed between the middle andupper units, means pivotally mounting the first lever means intermediateits ends, two movable contacts connected to the first lever meansadjacent its two ends, one of the contacts movable within an end unitand the other movable contact movable within the center unit, a secondlever means disposed between the middle and lower units, means pivotallymounting the second lever means intermediate its ends, two

'movable contacts connected to the second lever means adjacent its twoends, one of the contacts movable within the center unit, the othermovable contact movable within the lower unit, a piston member formingan extension of one of the movable contacts and movable within the unitad.- jacent to which is the unit in which the movable contact moves, anoperating rod movable axially of the assemblage, and means pivotallyinterconnecting the operating rod and the two lever means.

15. In a circuit interrupter of the fluid blast type, an arcextinguishing assemblage comprising two serially related arcextinguishing units disposed in axially aligned relation, rotatablelever means positioned between the two units, means pivotally mountingthe lever means intermediate its ends, contact means in one of the unitsfor establishing arcing therein including a movable contact operativelyconnected to the lever means adjacent one end thereof, other contactmeans in the other of the units for establishing arcing thereinincluding a movable contact operatively connected to the lever meansadjacent the other end thereof, fluid passage means interconnecting thetwo units, and substantially transverse fluid blast passage meansdisposed adjacent the region of arcin in One of the units to receivefluid through the first-mentioned passage means from the other unit anddirect it against the arc. 1

16. In a circuit interrupter of the fiuid blast type, an arcextinguishing assemblage comprising two serially related arcextinguishing units 7 disposed in axially aligned relation, rotatablelever means positioned between the two units, means pivotally mountingthe lever means intermediate its ends, contact means in one of the unitsfor establishing arcing therein including a movable contact operativelyconnected to the lever means adjacent one end thereof, other contactmeans in the other of the units for establishing arcing thereinincluding a movable contact operatively connected to the lever meansadjacent the other end thereof, fluid passa e means interconnectin thetwo units, and means at least partially of insulation defining aconstricted arcin slot adjacent the established arc in one of the unitsto facilitate extinction of the arc.

1'7. In a circuit interrupter, an arc extinguishing assemblagecomprising three serially related arc extinguishing units disposed inaxially aligned relation, a first lever means disposed between themiddle and upper units, means pivotally mounting the first lever meansintermediate its ends, two movable contacts connected to the first levermeans adjacent its two ends, one of the contacts movable within an endunit and the other movable contact movable within the center unit, asecond lever means disposed between the middle and lower units, meanspivotally mounting the second lever means intermediate its ends, twomovable contacts connected to the second lever means adjacent its twoends, one of the contacts movable within the center unit, the othermovable contact movable within the lower unit, a fifth movable contactmovable within one end unit, a third lever means, means pivotallymounting the third lever means, and means operatively connecting thefifth movable contact adjacent one end of the third lever means.

18. In a circuit interrupter, an arc extinguishing assemblage comprisingthree serially related arc extinguishing units disposed in axiallyaligned relation, a first lever means disposed between the middle andupper units, means pivotally mounting the first lever means intermediateits ends, two movable contacts connected to the first lever meansadjacent its two ends, one of the contacts movable within an end unitand the other movable contact movable within the center unit, a secondlever means disposed between the middle and lower units, means pivotallymounting the second lever means intermediate its ends, two movablecontacts connected to the second lever means adjacent its two ends, oneof the contacts movable within the center unit, the other movablecontact movable within the lower unit, a fifth movable contact movablewithin one end unit, a third lever means, means pivotally mounting thethird lever means, means operatively connecting the fifth movablecontact adjacent one end of the third lever means, and operating rodmeans connected to the three lever means to cause their simultaneousrotation.

19. In a circuit interrupter of the liquid break type, an arcextinguishing assemblage comprising three serially related arcextinguishing units disposed in superimposed relation, a stationarycontact disposed in each end unit, a movable contact cooperable witheach stationary contact to establish an arc in each end unit, twomovable contacts movable within the center unit, a first lever meansinterconnecting the movable contact associated with an end unit with oneof the two movable contacts associated with the center unit, a secondlever means interconnecting the movable contact associated with theother end unit with the other movable contact associated with the centerunit, and magnetic means in at least one of the units to cause lateralmotion of the arc established therein.

20. In a circuit interrupter, an arc extinguishing assemblage comprisingtwo serially related arc extinguishing units disposed in axially alignedrelation, rotatable lever means positioned between the two units, meanspivotally mounting the lever means intermediate its ends, a movablecontact connected to the lever means adjacent one end thereof andmovable within one of the two units, another movable contact connectedto the lever means adjacent the other end of the lever means and movablewithin the other unit, piston member forming an extension of thesecond-mentioned movable contact and movable into the first-mentionedunit, passage means interconnecting the two units so that fluid underpressure from one unit may flow through the passage means into the otherunit, and magnetic means in at least one unit to efiect lateral motionof the are established therein.

21. In a circuit interrupter, an arc extinguishing assemblage comprisingtwo serially related arc extinguishing units disposed in axially alignedrelation, rotatable lever means positioned between the two units, meanspivotally mounting the lever means intermediate its ends, a movablecontact connected to the lever means adjacent one end thereof andmovable Within one of the two units, another movable contact connectedto the lever means adjacent the other end of the lever means and movablewithin the other unit, a piston member forming an extension of thesecond-mentioned movable contact and movable into the first-mentionedunit, an operating rod movable axially of the two units, means pivotallyinterconnecting the operating rod and the lever means, and passage meansinterconnecting the two units so that fluid under pressure from one unitmay flow through the passage means into the other unit.

22. In a circuit interrupter, an arc extinguishing assemblage comprisingtwo serially related arc extinguishing units disposed in axially alignedrelation, rotatable lever means positioned between the two units, meanspivotally mounting the lever means intermediate its ends, a movablecontact connected to the lever means adjacent one end thereof andmovable within one of the two units, another movable contact connectedto the lever means adjacent the other end of the lever means and movablewithin the other unit, a piston member forming an extension of thesecond-mentioned movable contact and movable into the first-mentionedunit, an operating rod movable axially of the two units, means pivotallyinterconnecting the operating rod and the lever means, magnetic means inat least one unit to efiect lateral motion of the are establishedtherein, and a conducting member for engaging the operating rod inabutting relation to cause the closing motion thereof.

23. In a circuit interrupter, an arc extinguishing assemblage comprisintwo serially related arc extinguishing units disposed in axially alignedrelation, rotatable lever means positioned between the two units, meanspivotally mounting the lever means intermediate its ends, a movablecontact connected to the lever means adjacent one end thereof andmovable within one of the two units, another movable contact connectedto the lever means adjacent the other end of the lever means and movablewithin the other unit, passage means interconnecting the two units sothat the are established in one of the units may force fluid through thepassage means into the other unit, means defining a restricted slotadjacent the are established in one unit, and magnetic means for biasingthe are within the slot.

24. A circuit interrupter including operating rod means, rotatable levermeans making a substantially acute angle with respect to the operatingrod means, means pivotally mounting the rotatable lever meansintermediate the ends thereof, another rotatable lever means making asubstantially acute angle with respect to the operating rod means, meanspivotally mounting the said other rotatable lever means intermediate theends thereof, means interconnecting the operating rod means with bothrotatable lever means to cause their simultaneous rotation, the saidconnection being on opposite sides of the pivotal mounting of the tworotatable lever means,'a pair of movable contacts, means operativelyconnecting the pair of movable contacts adjacent opposite ends of thefirst said rotatable lever means and causing the motion of the pair ofmovable contacts in a direction substantially longitudinally of theoperating rod means, a third movable contact, means operativelyconnecting the said third movable contact adjacent one end of the saidother rotatable lever means and causing the motion of the said thirdcontact in a direction substantially longitudinally of the operating rodmeans.

25. A circuit interrupter including operating rod means, a pair ofmovable contacts, rotatable lever means making a substantially acuteangle with respect to the operatin rod means, means pivotally mountingthe rotatable lever means intermediate the ends thereof, anotherrotatable lever means making a substantially acute angle with respect tothe operating rod means, means pivotally mounting the said otherrotatable lever means intermediate the ends thereof, meansinterconnecting the operating rod means with both rotatable lever meansto cause their simultaneous rotation, the connection being on oppositesides of the pivotal mounting of the two rotatable lever means, meansoperatively connecting the said pair of movable contacts adjacentopposite ends of the first said rotatable lever means and causing themotion of the said pair of movable contacts in a direction substantiallylongitudinal of the operating rod means, a third movable contact, meansoperatively connecting the said third movable contact adjacent one endof the said other rotatable lever means and causing the motion of thesaid third movable contact in a direction substantially longitudinal ofthe operating rod means, piston means including a movable piston member,and means operatively connecting the movable piston member adjacent theother end of said other rotatable lever means.

26. A circuit interrupter including an are extinguishing assemblage, thearc extinguishing assemblage including two serially related areextinguishing units disposed in axially aligned relation, operating rodmeans extending axially of the arc extinguishing assemblage, rotatablelever means positioned between the two units and making a substantiallyacute angle with respect to the operating rod means, means pivotallymounting the rotatable lever means intermediate the ends thereof,another rotatable lever means disposed on the other side of one of theunits and making a substantially acute angle with respect to theoperating rod means, means pivotally mounting the said other rotatablelever means intermediate the ends thereof, means interconnecting theoperating rod means with both ro tatable lever means to cause theirsimultaneous rotation, the connection being on opposite sides of thepivotal mounting of the two rotatable lever means, a pair of movablecontacts, one of which moves in each of the two are extinguishing units,means operatively connecting the pair of movable contacts adjacentopposite ends of the first said rotatable" lever means and causing themotion of the pair of movable contacts in a direction substantiallyaxially of the arc extinguishing assemblage within the arc extinguishingunits, a third movable contact movable within said one of the arcextinguishing units, means operatively connecting the third movablecontact adjacent one end of the said other rotatable lever means andcausing the motion of the third movable contact in a directionsubstantially axially of the arc extinguishing assemblage.

27. A circuit interrupter of the liquid break type including an arcextinguishing assemblage, the arc extinguishing assemblage including twoserially related arc extinguishing units disposed in axially alignedrelation, operating rod means extending axially of the arc extinguishingassemblage, rotatable lever means positioned between the two units andmaking a substantially acute angle with respect to the operating rodmeans, means pivotally mounting the rotatable lever means intermediatethe ends thereof, another rotatable lever means disposed on the otherside of one of the units and making a substantially acute angle withrespect to the operating rod means, means pivotally mounting the saidother rotatable lever means intermediate the ends thereof, meansinterconnecting the operating rod means with both rotatable lever meansto cause their simultaneous rotation, the connection being on oppositesides of the pivotal mounting of the two rotatable lever means, a pairof movable contacts, one of which moves in each of the twoarc-extinguishing units, means operatively connecting the pair ofmovable contacts adjacent opposite ends. of the first said rotatablelever means and causing the motion of the pair of movable contacts in adirection substantially axially of the arc-extinguishing assemblagewithin the arc-extinguishing units, a third movable contact movablewithin said one of the arcextinguishing units, means operativelyconnecting the third movable contact adjacent one end of the said otherrotatable lever means and causing the motion of the third movablecontact in a direction substantially axially of the arc-extinguishingassemblage, a piston member movable within the said one of thearc-extinguishing units, and means operatively connecting the pistonmember adjacent the other end of the said other rotatable lever means.

WINTHROP M. LEEDS. JAMES M. CUMMING.

REFERENCES CITED The following referenlces are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 862,513 Robinson Aug. 6, 19071,847,463 Austin Mar. 1, 1932 2,039,054 Boden et al Apr. 28, 19362,084,885 Biermanns June 22, 1937 2,098,801 Erben Nov. 9, 1937 2,141,279Sadler Dec. 27, 1938 2,154,515 Leeds Apr. 18, 1939 2,155,263 FiurscheimApr. 18, 1939 2,292,547 Sadler Aug. 11, 1942 2,394,046 Dickinson Feb. 5,1946

